Add full shell, replaceable Omics adapter and bilingual interaction

Implement approved specification #32 and tickets #33-#37. Keep host authentication server-verified and pin session interaction language. Compile scoped base selectors for browser compatibility and retain full gutters during CSS pruning.

backend/src/routes/sessions.ts

@@ -13,6 +13,7 @@ import type { MaintenanceBarrier } from "../runtime/maintenance-gate.js";
 import { hasPermission, isPrincipalContext, requirePermission } from "../auth/authorization.js";
 import { splitCanonicalModelId, type RuntimeModelCatalog } from "../models/runtime-model-catalog.js";
 import type { CatalogRepository } from "../catalog/types.js";
+import { interactionLanguage } from "../tht/interaction-language.js";
 
 const BOOTSTRAP_FAILURE_MESSAGE =
   "Session startup failed. Check configuration and connectivity, then Resume the session.";
@@ -381,8 +382,13 @@ export function sessionRoutes(
   app.post("/sessions", async (req, reply) => {
     const b = req.body as {
       question: string; name?: string; workspace?: string; workspaceId?: string;
-      provider?: string; model?: string; thinking?: string;
+      provider?: string; model?: string; thinking?: string; interactionLanguage?: unknown;
     };
+    const language = interactionLanguage(b?.interactionLanguage);
+    if (!language) return reply.code(400).send({
+      code: "invalid_interaction_language",
+      error: "interactionLanguage must be a well-formed BCP-47 language tag",
+    });
     if ((b.provider === undefined) !== (b.model === undefined)
       || (b.provider !== undefined && (typeof b.provider !== "string" || typeof b.model !== "string" || !b.provider || !b.model))) {
       return reply.code(400).send({ error: "provider and model must be supplied together" });
@@ -507,6 +513,7 @@ export function sessionRoutes(
         ({ id } = await runner.sessionNew({
           question: b.question, name: b.name, workspaceConfigPath,
           workspaceId, workspaceRevision, provider, model, thinking,
+          interactionLanguage: language,
         }));
         manifestPersisted = true;
         if (revisionLease) {
@@ -520,6 +527,7 @@ export function sessionRoutes(
       } catch { return storageFailure(reply); }
       const options = {
         provider, model, thinking,
+        interactionLanguage: language,
         author: principal.displayName ?? principal.subject,
         principal,
         question: b.question,
@@ -664,6 +672,13 @@ export function sessionRoutes(
   app.post("/sessions/:id/resume", async (req, reply) => {
     const id = (req.params as any).id;
     const principal = getPrincipal(req);
+    if (Object.hasOwn(req.body ?? {}, "interactionLanguage")
+      || Object.hasOwn(req.body ?? {}, "interaction_language")) {
+      return reply.code(400).send({
+        code: "interaction_language_pinned",
+        error: "Resume uses the session's persisted interaction language; overrides are not accepted",
+      });
+    }
     return withSessionLifecycle(id, async () => {
       let settings: Settings;
       let located: LocatedSession | undefined;
@@ -681,6 +696,7 @@ export function sessionRoutes(
       const saved = manifest as {
         provider?: string; model?: string; thinking?: string;
         workspace_id?: string; workspace_revision?: string;
+        interaction_language?: string | null;
       };
 	  const requested = (req.body ?? {}) as { provider?: string; model?: string; thinking?: string };
 	  if ((requested.provider === undefined) !== (requested.model === undefined)
@@ -719,6 +735,12 @@ export function sessionRoutes(
         });
       }
       try { settings = await d.getSettings(principal); } catch { return storageFailure(reply); }
+      let language = saved.interaction_language;
+      if (language == null) {
+        try {
+          language = (await runner.ensureInteractionLanguage(id, workspaceConfigPath)).interaction_language;
+        } catch { return reply.code(503).send({ error: RESUME_FAILURE_MESSAGE }); }
+      }
       // This check belongs inside the per-session lock: a preceding cold Resume may have
       // installed a running runtime while this request was waiting.
       const existing = d.mgr.get(id);
@@ -737,6 +759,7 @@ export function sessionRoutes(
       });
       const options = {
         provider: selected.provider,
+        interactionLanguage: language,
         model: selected.model,
         thinking: saved?.thinking ?? settings.thinking,
         author: principal.displayName ?? principal.subject,